Johnymd

I'm in the midle of a 1JZ conversion into my 240Z and at the moment I'm looking at the fuel delivery system. I'm planning on using the old fuel tank feading a fascet red top, filter, then surge tank. Surge tank then returns to fuel tank. For the HP side I'm going from the bottom of the surge tank into a bosch 044 then straight to the engine. The return from the engine then goes back into the top of the surge tank. So, my question is what size return do I need so as not to build up too much pressure on idle at the fuel rail? I think the pressure is regulated by opening the return (please correct me if I'mm wrong). I fitted new copper line a couple of years ago but they are the same size as the originals. Any advice welcome.